Method of manufacturing linoleum compositions



METHOD OF MANUFACTURING LINOLEUM COMPOSITION Filed Sept. 26, 1942 HIGHTACKINESS a i G 0 gvwq/wtoo L E q m TACKINESS 32 7 'LOW HIGH 33TEMPERATURE M ITP t... MM, 945 2,311,014

METHOD OF MANUFACTURING LINOLEUM COMPOSITIONS Virgil Spencer, EastPetersburg, Pa., assignor to Armstrong Cork Company, Lancaster, Pa., acorporation of Pennsylvania Application September 25,1942, Serial No.459,846

5 Claims. (01. 18-55) This invention relates to the manufacture oflinoleum mix is increased, there is a first temlinoleum and, moreparticularly, to the forming perature range in which the tackiness ofthe of linoleum composition by extrusion. linoleum mix progressivelyincreases, a second In the manufacture of linoleum, drying oil is Ihigher temperature range in which the tackiness first oxidized,thickened and bodied by any one reinains substantially constant andstarts to deof the well-known processes to form a semi-solid, crease,and a third, still higher temperature range plastic mass, which is mixedwith a resin, such in which the tackinessv greatly decreases. This asrosin, ester gum, kauri gum,. or the like, to protemperature isunusually high for the working duce a so-called linoleum cement; Linseedoil is of'linoleum mixes, much'above normal-calendergenerally used butother drying or-semi-drying in ing temperatures and substantially higherthan oils such as soya bean oil menhaden oil, and the curingtemperatures. If the mix is heated to a lik may be and often are used.Ordinarily, temperature above the range in which the tackilinoleumcement comprises 65% to 85% drying ness start to decrease, and into therange where oil and 35% to resin. Linoleum mix is'pretackinessmaterially decreases, the linoleum mix pared by admixing linoleum cementwith suitable 15 may be extruded or flowed through a die to form fillerssuch a cork, wood flour, and the like, a uniform sheet of linoleumcomposition. By mineral filler and suitable pigments for coloring. thisdiscovery I hav made possible for the first Th linoleum mix, in the formof particles or time the extrusion of linoleum composition by lumps, maybe passed between calendering rollers heating the surface of the mixadjacent the exto form a sheet of linoleum composition which is 20trusion die to such extreme temperatures that applied to andconsolidated on a backing fabric frictional resistance is materiallyreduced.

such as a web of burlap, to produce the product These and other novelfeatures will appear known to the art a plain linoleum, or the mix morefully in the following detailed description may be granulated anddeposited through stencils of the process which will be given inconjunction directly onto a backing fabric and then pressed with theattached drawing of an apparatus for to form molded inlaidlinoleum. Itis necessary carrying out the process, in which:

to cure or mature the linoleum under heat to Fig. l is a schematicrepresentation of an appolymerize the partially processed drying oil andparatus for carrying out my novel process and harden the linoleum.Maturing is usually acincludes a longitudinal sectional view of onecomplished by suspending the linoleum in-fes i" form of an extrusiondevice and -a schematic toons in stoves heated to a temperature of aboutrepresentation of a blanked type consolidating F. to F. for a number ofdays. calender; A

Many unsuccessful attempts have been made Fig. 2 is an end elevationalview of the extrusion to form linoleum mix into relatively thin sheetsdevice oi Fig. l; I of uniform thickness, or other desired shape, by 35Fig. 3 i a diagrammatic representation by heating the mix and forcingit, under pressure, graph of the comparative tackiness of a linoleumthrough an extrusion die of suitable shape in the mix at differenttemperatures; and, same manner as in the extrusion of plastics in- Fig.4 is a diagrammatic representation of an eluding thermoplastic binderand fillers. The alternative heating means for the extrusion defrictionbetween the outer or' skin surface of the vice shown more fully inFig. 1. I

mix and the wall surface of the extrusion tube is- Referring to thedrawing and more particularly so great that the mix cannot be extruded.In to Figures 1 and 2, an extrusion device or gun G some attemptshydraulic pressures suflicient to mounted on a suitable support S bymeans of a rupture a heavy metal extrusion tube have been bracket l0 andbolts H i shown for extruding a applied without extrusion of thecomposition. relatively'thin, wide ribbon or sheet of linoleum Reducedtemperatures have been tried -without composition M. The sheet M ispreferably ap-. success and elevated temperatures have increased plieddirectly to a backing strip B, such as a strip the tackiness Y andfrictional resistance of the .01 burlap. which may be supported by oneor more composition. Raising the j temperature of a rollers 12 rotatablymounted on suitable "trunlinoleum mix increases itsplasticity but,unlike nions H. The backing strip B and the 'sheetof many otherthermoplastic materials, increasing linoleum composition M'- are pressedtogether the plasticity also increases the tackiness which. by aconventional heated consolidating calender in turn increases thefriction and prevents ex- C to form asheet f linoleum L suitabl upon-trusion. curing for use as a covering for floors, walls or I havediscovered that as the temperatureoi a 66 other surfaces. For purposesof illustration. the

thickness ofthe backing B and the sheet of coin- The cylinder I4 isprovided with a jacket 25 welded thereto to provide a heating chamber 26between the jacket 25 and the outer surface of the cylinder Hi. Thejacket 25 is provided with an inlet connection 21 which communicateswith a source of high temperature heating fluid, such as hot oil and anoutlet connection 28 which communicates with a drain or any suitablerecirculating means. High temperature steam may be used for heating theextrusion gun, in which as is schematically represented by the line b-c.

resented by the line (1-1) when the temperature reaches the point 0' andthat the tackiness continues to'decrease as the temperature increases topoint d. It has been found that the peak or greatest-tackiness occurs ata point along line bc and at a temperature in the range of approximately300" F. to 400 F.v with a linseedoil-rosin type cement. It has also beenfound that at approximately a temperature range of 400-750" F. thetackiness of the linoleum mix has been lowered sufiiciently to enablethe mix to be extruded at reasonable ressures. It should be understoodthat the temperature ranges will event, the inlet and outlet connections2! and .28 are preferably reversed. Thus hot fluid or gas is circulatedthrough the chamber 26 for heating at least the forward end portion ofcylinder i4 and the forward end wall 22, all as more fully hereinafterdescribed. The cylinder [4 is also provided with an inlet tube 29through which the particles or lumps of linoleum mix may be fed into thecylinder for extrusion upon retraction of the piston 15. A cap 30 isprovided for closing tube 29 when mix is not being fed into thecylinder. v

Fig. 4 illustrates a modified embodiment of the means for heating theoutlet end of the extrusion gun G. The jacket 25 is shorter than thejacket 25 of Fig. 1 and an annular electrical heating coil 32 with itsinsulation 33 is mounted on the lower end of the gun G for heating thelower end'of tube l4 and wall 22. With the construction of Fig. 4,additional heat may be supplied for heating the additional thickness ofmetal. Further, it may be desirable when extrud-- ing some linoleummixes to heat the lower end of the tube l4 and wall 22 to a temperaturehigher than the temperature maintained in the chamber 26 bythe hot fluidor gas therein.

To operate the extrusion gun G, the hand wheel 20 is manually rotated.to withdraw the piston l5 to the upper end of the cylinder. The cylinderis then filled with linoleum mix which 'preferably has been warmed to aplastic condition. Rotation of the hand wheel 20 in the oppositedirection moves the iston -I5 forwardly toward the head end ofthe'cylinder and applies pressure to thelinoleum mix to force it throughthe orifice 23. The inlet and outlet ends of outlet orifice 23 is shownas flared but the illustration is not intended to show the precisecontour of the orifice 'as this will be determined by the character ofthe mix being extruded, its shape and thickness and the pressurenecessary to extrude the material. a

4 -Referring more particularly to Fig. 3 of the drawing, the ordinaterepresents the temperature range and the abscissa schematicallyrepresents the degree of tackiness. The ratioof tackiness totemperatureis schematically represented by the curve a-d. Starting at alow temperature, as the temperature is increased, the tackinessincreases as is represented by the line a.-b. An additional increase inthe temperature over a considerable range does not materially change thetackiness, it remaining substantially constant vary depending upon theconstituents of the linoleum mix and that the curve ad is merely aschematic representation of the ratio of tackimess to temperature. Thecurve a--d will also vary according to the constituents of the linoleummix, but, for any mix, the curve will have three portions correspondingto lines, a-b, bc, and cd.

When extruding any of the present linoleum mixes, it is preferable thatthe body of linoleum mix be heated to increase its plasticity beforebeing placed in the extrusion gun. It being understood that there may bea small amount of heat imparted to the body of linoleum mix While in theextrusiongun. The temperature of the mix falls within the rangeschematically represented by the portion 0-!) of the curve (1-11 and ispreferably not over about 350 F. The temperature of the heating fluidwithin the chamber 26 and/or of coil 32 'is such as to flash heat onlythe surface skin portion of the mix to the lubricating temperature,which temperature is within the range represented by the portion cd ofthe curve a-d and is both 'mate- 'rially above the temperature at whichsticking occurs and above the flow pointiof the linoleum cement. It ispreferable that the linoleum mix be extruded at the lowest possibletemperature.

The exact temperature for any particular mix of the mix.

The rate of flow of mix through the extrusion I dieand the temperatureof the extrusion die are such that only the outer skin portion of thelinoleum mix is heated to the high lubricating or substantially fluidtemperature, at which temperature. the tackiness is so reduced that themix can 'be flowed through the die. This last mentioned temperature willalways be-within the range schematically represented by the line c-d andwill usually be within the range of about between 400-750 F.

By the term extrusion die, it is intended to include all walls past thesurfaces of which the lineloum mix is flowed under extrusion pressure.In the apparatus shown in the drawing, the term extrusion die includesboth the forward end ortion and the end wall 22 of cylinder I4.

It is obvious that various modifications may be 'made from the methoddisclosed in connection with the illustrated apparatus without de- V2,s7i,o74

7 sheets of different transverse configurations; the

linoleum composition, after extrusion may be put to uses other than as afloor or wall covering; and

a plurality of extrusion guns may be used simul-.

taneously to form a single relatively wide sheet of linoleumcomposition. Additionally, it is contemplated that extrusion means maybe used which is. so constructed and arranged asto continuously extrudelinoleum composition and which is provided withmeans for continuouslyfeeding linoleum mix into theextrusion means.

What is claimed is:

1 In a process of forming a shaped body, such as a sheet, of linoleum byextrusion of a linoleum mix including a semi-solid drying oil and resinbinder together with filler particles, said. mix

having the physical characteristics of progressively increasingintackiness in an initial tem;

4. ma process of forming a shaped body, such as asheet, oi! linoleum byextrusion of a linoleum mix including a semi-solid linseed oil and rosinbinder together with filler particles, said mix having the physicalcharacteristics of progressively increasing in tackiness in an initialtemperature range up to about 300 F. and decreasing in 'tackiness in therange between about400 F. and

perature range, and decreasing in tackiness to a point below thetackiness of the intial range in a higher temperature rangesubstantially above, the initial temperature range, said higher rangelying above normal calendering temperatures and substantially abovecuring tempera.- tures, the steps of applying pressure to the linoleummix to force the same through an extrusion die and heating the surfaceonly of the mix incontact with the die to a temperature within saidhigher range and above 400 F.' where tackiness is decreased to a pointbelow the tackiness of the initial range and extrusion made ,possible. i

2. In a method in accordance with claim 1, the additional step ofpre-heatingthe linoleum mix to a plastic" condition prior to theapplication of pressure for extrusion. 4 r

3. In a method in accordance with claim '1, the

' additional step of pre-heating the linoleum mix to a temperature up toabout 350 F. prior to the application of pressure for extrusion.

as a sheet, of linoleum by extrusion of alinoleum mix including asemi-solid drying oil and'resin binder together with filler particles,said mix having the physical characteristics of progressively increasingintackiness in an initial temperature range,- maintaining substantiallyconstant tackiness in a second temperature rangeabove the initial range,and greatly decreasing in tackiness in a third temperature range abovethe sec-' 0nd temperature range, saidthird temperature 0 range lyingabove normalcalendering temperatures; substantially above curingtemperatures,

and in the range between 400 F. and750 F., the

stepsof applying pressure to the linoleum'mix to force the same throughan extrusion die and heating the surface only of the mix in contact withthe die to a temperature within said third range where tackiness isdecreased to a point below the tackiness of the initial rangeandextrusionmade possible.

I VIRGIL SPENCER.

